At some places graffiti is legal in the city. They encourage artists to create graffiti on walls of old abandoned factories. Some says this is not a graffiti anymore because a real graffiti has to be illegal. I dont know too much about this, but I like this kind of “professional” works better then pure tags everywhere in Budapest.
Hard to catch these long wall with a single camera so I created a video time ago about it. You can see it here. And other graffiti here.
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Look up the definition of graffiti. No where does it say it is illegal. Street art, or graffiti, only upsets residents if done in view, but “real graffiti” does not have to be illegal. That is a common misconception.
Tagging is the word you should be using. Because that is just an abomination and disgrace to everyone in the street art world, including myself.